Piston skirt adjuster



A. F. YODER M m.

Q PISTON SKIRT ADJUSTER Filed Nov. 17, 1934 Patented Dec. 17, 1935 PATENT OFFICE 2,024,620 PISTON V SKIRT ADJUSTER Alfred Floyd Yoder, Akron, and David Milton Yoder, Barber-ton, Ohio Application November 17, 1934, Serial No. 753,516

8 Claims This invention relates to pistons and more particularly to a means for expanding the skirt of a a piston so as to take up any play between the piston and the cylinder wall of an internal combustion engine.

7 An object of this invention is to provide a means for enlarging the skirt of a piston which is readily adjustable so as to eliminate any piston slapping due to the wearing of the skirt and the cylinder wall. 7 7

Another object of this invention is to provide in combination with a piston having a split skirt means operable from below for adjusting the size a of the skirt of the piston without removing any of the parts of the piston from the cylinder.

A further object of this invention is to provide in-a device of this kind means whereby the adjusting means is automatically locked in adjusted position so that the enlarged or adjusted piston will not get out of adjustmentin the operation of the engine.

A still further object ofrthis invention is .to provide a means for adjusting the diameter of the skirt of a piston which is so'constructed that 25 it can'be readily mounted in any of the'present types of pistons provided with skirts and when once mounted, the adjusting means may be readily actuated to change the size of the diameter of the skirt without removing the piston or its connectionsfrom the engine.

The above and various other objects and advantages of this invention will in part be described and in part be understood from the following detailed description of the present preferred embodiment, the same being illustrated in the accompanying drawing wherein:

Figure -1 is a detail side elevation of a conventional piston having a split skirt in which a device constructed according to the. preferred embodiment of thisinvention is mounted.

Figurel2 is a transverse section taken on the line 2-2 of Figure 1. I

Figure 3 is a vertical section taken on the line 3-3 of Figure 2.

the piston adjusting means removed from the piston. I

Figure 5 is a modified form of adjusting means for the skirt of the piston.

Referring to the drawing wherein like characters of reference designate corresponding parts throughout the several views thereof, the letter F designatesv generally a piston provided with a skirt portion S which is' split, as at I3. In internal combustion engines, after the engine has Figure 4 is an enlarged detail side elevation of the cylinders and the cylinder walls wear to such an extent that there is a considerable slapping or loose play between the skirt of the piston and the cylinder wall, which play permits the rela- 5 tively free passage of oil or the like from below the piston onto the upper portion thereof and in this manner, a substantial pumping of oil is effected which oil is then discharged out of the cylinder through the exhaust ports of the engine. '10 Inorder to prevent the pumping of oil and the slapping of the piston, the usual method is to rebore and insert pistons having a diameter to slidably and snugly engage the rebored cylinders or to insert larger pistons inthe unrebored cyl- 15 inders. This latter method, however, has the disadvantage of inserting a round piston in a cylinder, the walls of which are not round but slightly oval on opposite sides.

Where either of the above mentioned methods is used to prevent pumping of oil and to increase the compression, it is necessary to take the motor apart, which procedure involves the removal of the head of the motor, removal of the oil pan and disconnection of the pistons from the crank shaft. 7 In order, therefore, to provide a means whereby the original piston having a split skirt may be enlarged without requiring the taking apart in such a complete manner of the motor, we have provided a skirt adjusting means comprising a pair of. pins or abutments Iii which are disposed one on each side ofthe split portion I3 of the skirt S and at a point intermediate the ends of the skirt S. The pins If! in the present instance are headed pins which are secured in the wall of the skirt S in any suitable manner so that the outer ends of the pins It will not project beyond the periphery of the skirt S and thereby injure the wall of the cylinder of the engine. The pins 10 in the present instance are inserted in suitable openings and fixed in the openings but it will, of course, be understood that the pins or abutments it may also be made integral with the material of the skirt S as where the pins I0 are cast orformed at the same time that the piston proper is cast.

A skirt expanding means generally designated as .I I engages the pins or abutments I0 and comprises opposed pairs of angularly related arms I2 and I l connected together'at their convergent endsgas by a coil I5 which loosely engages about a pin I0 inwardly of the head thereof. The lower or divergentv end of the opposed arms I2 are con- 5 n'ec'ted together by means of a coil or loop I6 5 which loosely engages about an adjusting bolt I I having a head I8 provided with a kerf IS. The bolt I! has a nut 20 threaded thereonto and this nut 28 has a pair of parallel arms 2I disposed in opposed relation and provided with openings 22 in which the end portions 23 of the opposed arms I4 are loosely received. The opposed ends of the arms or extensions 23, when the nut 20 is drawn toward the eye or loop I6, are adapted to contact with the peripheral portions of the threads on the bolt IT and thereby act as a locking means to lock the nut 26 and prevent the bolt I? from turning when the pistons are moving up and down within the cylinder. The opposed arms I2 and I4 form a parallelogram and the bolt IfI transects the parallelogram through opposite corners,

In Figure 5 there is disclosed a modified form of adjusting means for the skirt S of the piston wherein the arms I2 and I4 are formed as a toggle and engage at their convergent ends about the pin Ill. The toggle member I2 is pivotally secured, as at 24, to an angle member 25 and the upper or divergent end of the toggle member I4 is pivotally secured, as at 26, to an angle nut member 21 threaded onto an adjusting bolt IT. The bolt I I passes through the angle member 25 and the relatively rigid arms I2 and I4 form a parallelogram in the same manner as the disclosure shown in Figure 4.

In the use and operation of the skirt adjusting means hereinbefore described where the device is mounted on a piston of an engine which has been in operation for a period of time, the piston is initially withdrawn from the cylinder of the engine and the walls of the skirt S bored to receive the pins I which are inserted with the heads on the inner side thereof. The outer ends of the pins I 0 may be upset or secured in any other suitable manner in the walls of the skirt S on opposite sides of the slot I3. The pins Ill are passed through the eyes I of the adjusting member before being fastened in the wall of the skirt and the adjusting bolt I! will be loosened so that no pressure will be applied initially to the nut 20. It will, of course, be understood that the arms I2 and I I are preferably curved longitudinally, as shown in Figure 2, so that they will lie fiat against the inner circle of the skirt S. After the adjusting member II has been mounted within the skirt S, the bolt I1 is turnedso as to draw the arms I2 and I4 toward each other under the action of the bolt I! which will tend to force the divergent ends or eyes I5 apart and this action will cause expansion of the slot I3 and the walls of the skirt S. After the adjusting member I I has been applied to the piston P, the skirt S may be readily adjusted by merely removing the oil pan from the bottom of the motor and then inserting a screw driver into the cylinder for engagement in the kerf I9 of the screw head I8.

In the disclosure shown in Figure 4, the adjusting member II is constructed from a piece of wire which is formed with the opposed eyes I5 and the eye I6. It will also be apparent that the tightening of the nut 20 will tend to put the arms I2 and I 4 under considerable tension so that the skirt S will be expanded and held in its expanded position and in addition thereto, the skirt S will continue to be expanded as the periphery of the skirt wears down.

It will be obvious from the foregoing that an exceedingly simple piston adjusting m'eans has been disclosed whereby the diameter of the skirt of the piston may be adjusted without removing the piston from the cylinder once the device has been applied and that the diameter of the skirt of the piston will automatically change so long as the device is under tension, thereby providing 5 an automatically operated adjusting means which will act to maintain the skirt of the piston of a diameter suflicient to prevent slapping of the piston within the cylinder.

What is claimed is:-- 10 1. An adjusting means for the skirt of a split piston, comprising a pair of pins adapted to be secured to the inside of the skirt of the piston one on each side of the split portion thereof, pairs of angularly related members secured one pair to each pin, each member of each pair being movable relative to each of the other members, threaded means engaging said angularly related members to adjust the angular relation of said members one relative to another whereby to enlarge the split portion of the skirt of the piston and locking means carried by one member of each pair of angularly related members to hold the threaded means against turning.

2. An adjusting means for the skirt of a split 5 piston, comprising pairs of angularly related arms adapted to be disposed one pair on each side of the split portion of the piston, means for securing the convergent ends of each pair of arms to the wall of the piston, and means extending 0'- between the divergent ends of the arms to draw said divergent ends toward each other and to thereby force the convergent ends of the arms apart and thereby expand the skirt of the piston.

3. An adjusting means for the skirt of a piston,

comprising a pair of pins adapted to be mounted in the skirt of a piston and to project inwardly thereof one on each side of the split portion of the piston, opposed pairs of angularly related arms, an eye formed integrally with the convergent ends of each pair of arms, said eye of each pair of arms loosely engaging about a pin, a bolt extending between the divergent ends of the arms, two of said arms having an integral eye at the adjacent divergent ends thereof, a

nut threaded onto said bolt and provided with alined openings disposed at right angles to the bolt, the other two arms at the divergent ends thereof having an extension engaging within said opening, said extension upon tightening of the nut frictionally engaging the periphery of the bolt whereby to lock the bolt against turning, tightening of the nut on the bolt drawing the divergent ends of the arms together to thereby expand the split portion of the skirt.

4. An adjusting means for the skirt of a split piston, comprising a pair of pins adapted to be mounted in the skirt of the piston on the inside thereof and to project inwardly of the skirt one on each side of the split portion, a pair of o toggle members adapted to be disposed on each side of the split portion of the piston, said toggle members swingably engaging at their convergent ends about a pin, an adjusting bolt extending between the divergent ends of the toggle members, a plate secured to the ends of one of each pair of toggle members and loosely engaging about the bolt, and. a second plate secured to the other of each pair of toggle members and threadably engaging the bolt.

5. An adjusting means for the skirt of a split piston comprising a pair of pins adapted to be secured to the insideof the skirt, one on each side of the split portion thereof, pairs of angularly related members secured one pair to each pin, each member of each pair being movable relative to each of the other members, a right angularly related eye carried by' two of said members, a bolt extending through said eye and a nut 'for receiving the bolt carried by the other two of said members.

6. An adjusting means for the skirtof a split piston comprising a pair of pins adapted to be secured to the inside of the skirt one on each side of the split portion thereof, pairs of angularly related members secured one pair to each pin, each member of each pair being movable relative to each of the other members, a right angularly related eye carried by two of said members, a bolt extending through said eye, a nut for receiving the bolt, and means integral with the ends of said other two of said members to mount the nutin axial alinement with said eye.

7. An adjusting means for the skirt of a split piston comprising a pair of pins adapted to be secured to the inside of the skirt one on each'side of the split portion thereof, pairs of angularly related members secured one pair to each pin, each member of each pair being movable relative to each of the other members, a right angularly related eye carried by two of said members, a bolt extending through said eye, a nut for receiving the bolt and confronting nut engaging pins integral with the ends of said other two members, said nut having alined openings to loosely receive said pins and the inner ends of said pins frictionally contacting with the periphery of said bolt within the nut to hold the bolt against turning.

8. An adjusting means for the skirt of a split piston comprising a pair of pins adapted to be secured to the inside of the skirt one on each side of the split'portion thereof, pairs of angularly related members secured one pair to each pin, each member of each pair being movable relative to each of the other members, a right angularly related eye carried by two of said members, a U-shaped nut having a threaded opening in the bight thereof, said nut having a pair of alined openings in the parallel legs thereof, a pair of confronting nut engaging pins carried by the other two of said members and engageable in the openings of the nut and a bolt extending through said eye and threadably engaging said nut, said pins being movable toward the bolt upon expansion of the skirt whereby to frictionally hold the bolt against turning.

' ALFRED FLOYD YODER. DAVID MILTON YODER. 

